Eubacteria

The eubacteries ( true bacteria ) or Eubacteria are a major subdivision of the Procaryote S, including/understanding all the Bactérie S (excluded the Archéobactérie S). One can quote for example Chlorobactéries (with which one can associate, according to the endosymbiotic Théorie, the Chloroplaste S), Protéobactéries (including the Mitochondrie S according to the same theory), the Cyanobactérie S, the Mycoplasme S ( Mollicutes ), the Entérobactérie S, the Pseudomonade S and the majority of the Bactérie S gram-positive.

Systematic position

According to Thomas Rider-Smith, they form a group paraphyletic (the Neomura , gathering Archées and Eucaryotes, are origineraient in their center), whereas, classically since Carl Woese, they only constitute one of the three empires of alive the .

Note: Not to confuse with the Eobacteria , taxon paraphyletic gathering most primitive of the bacteria, Chlorobacteria and Hadobacteria.

Characteristics

The eubacteries are distinguished on the one hand eucaryotes by their cellular structure (the procaryotic structure) one of the characteristics is to be without core, and on the other hand archées by various aspects chemical (of which the structure of the cellular membrane) and genetics.

Biological importance

If the diversity of the forms is low, the eubacteries occupy the majority of the mediums, and constitute certainly, of many cells and perhaps in mass, most of the alive one. They fill of the fundamental functions in the terrestrial ecosystem, as for example in the cycle of nitrogen or sulfur. When it is considered that the mitochondries and the chloroplasts are symbiotic eubacteries, that includes also the photosynthesis and the metabolism of oxygen (the eubacteries are at the origin of all the oxygen of the atmosphere), and they are thus the main door of all the energy which makes function living it. They play also a paramount role in the organic waste recycling. The oldest known fossils, the Stromatolite S, are of bacterial origin and are gone back to 3,5 billion years.

Classification

Traditional classification distinguishes, on the basis of metabolism, the photosynthetic Bactéries and the Bactéries chimiotrophes.

The systematic modern one, based on the genetic analyzes, distinguishes from many groups (see table opposite). One will note, inter alia, the Cyanobactérie S, an important group of photosynthetic bacteria.

Eubactéries and the Man

Historically, and perhaps still in the general spirit, the bacteria are associated with the diseases. Indeed, of many parasites are bacteria (the reverse is not true). The study of the bacteria was dominated a long time by pathology, and, to a lesser extent, the technical applications (inter alia fermentation, whether is to support it or fight it).

Habitat and metabolism

One finds eubacteries in almost all the mediums where the life appears possible. According to the lines, one finds of them phototrophes (drawing their energy from the light), chimiotrophes (finding their energy of nonorganic chemical gradients), heterotrophic (finding their energy in the organic matter, whether it is alive (parasitism) or dead); one finds aerobes or anaerobes of them strict.

See too

• Reigns of alive the
• Bacterium

Random links:

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